1. Field of the Invention
The present invention relates to a lens apparatus having an adjusting structure for correcting displacement and inclination of the optical axis of an optical device and relates to an optical apparatus including the lens apparatus.
2. Description of the Related Art
In response to the recent need for an improvement in the quality of zoom lens systems included in optical apparatuses, such as interchangeable lens systems for single-lens reflex cameras, an improvement in the accuracy in maintaining lens units constituting the zoom lens systems has been required. Accordingly, an optical apparatus having an adjusting structure for adjusting the displacement and inclination of the optical axis of a lens unit caused by production errors has been proposed.
As a known optical apparatus, there is the lens apparatus disclosed in Japanese Patent Laid-Open No. 2003-279822. This lens apparatus has at least three adjusting screws, whose height can be adjusted in the optical axis direction, that are provided predetermined distances apart from each other. The lens apparatus includes a ring plate having notches for partially exposing the heads of the adjusting screws, a lens supporting frame attached to the inside of the lens barrel frame through the ring plate, and a spring member that urges the lens supporting frame toward the adjusting screws.
At least two eccentric screws that are disposed in contact with the peripheral area of the lens supporting frame with predetermined distances between each other and an elastic member for receiving the movement of the lens supporting frame caused by the rotation of the eccentric screws are provided on the inner periphery of the lens barrel frame. A structure configured to adjust the inclination of the lens by the adjusting screws and to adjust the axial center of the lens by the eccentric screws is disclosed.
Another known lens apparatus is disclosed in Japanese Patent Laid-Open No. 2000-206389. This lens apparatus includes a first frame that holds a lens or a lens barrel, a second frame that supports the first frame by an elastic section, and a third frame that supports the second frame by another elastic section. The lens apparatus further includes two adjusting members that are provided on the second frame while being in contact with the first frame and that adjust the inclination of the optical axis and the parallel movement of the optical axis. The lens apparatus further includes two adjusting members that are provided on the third frame while being in contact with the second frame and that adjust the inclination of the optical axis and the parallel movement of the optical axis, respectively.
A structure configured to adjust the inclination and eccentricity by operating the adjusting members and by using the deformation of the elastic sections is disclosed.
According to the apparatus disclosed in Japanese Patent Laid-Open No. 2003-279822, adjusting screws and eccentric screws are operated from the optical axis direction. Therefore, when an adjusting operation is to be carried out while the apparatus is being actually used, jigs and the operator's hands used for tightening the adjusting screws and eccentric screws are easily captured in the image, and this may interfere with the adjusting operation. Based on the structure of the apparatus, it is possible to adjust the outermost lens units among the lens units constituting the zoom lens system. However, since it is difficult to adjust the lens units disposed near the center among the lens units constituting the zoom lens system, flexibility in the optical design is reduced.
The apparatus disclosed in Japanese Patent Laid-Open No. 2000-206389 allows adjusting members that adjust the inclination of the optical axis and the parallel movement of optical axis can be operated in a direction orthogonal to the optical axis. However, the adjusting members that adjust lenses at predetermined positions form an overlapping structure, causing an increase in the size of the lens barrel.